Vegetable Proteomics: The Detection of Ole e 1 Isoallergens by Peptide Matching of MALDI MS/MS Spectra of Underivatized and Dansylated Glycopeptides

Ole e 1 (NCBI entry gi|14424429) is the major allergen of Oleaceae family. Multiple isoforms and variants are present in varying degrees of distribution. In this report, we present a new approach to the resolution of multiple forms of Ole e 1 from whole antigen extracts, based on a preliminary chemical fractionation procedure followed by MALDI MS and MS/MS measurements. The characterization of Ole e 1 isoallergens was accomplished through the identification of the amino acid sequence including the glycosylation site and the structure of the glycan moieties. The structure feature of the identified Ole e 1.0102 (gi|2465127), main olive allergen [Olea europaea] (gi|13195753), Major pollen allergen Ole e 1 (gi|33329740) andOle e 1c (gi|1362131) is represented by the point mutation K106→I and by the presence of a glycan moiety. Two other variants Major pollen allergen (Allergen Ole e1) (Ole e I) (gi|14424429) and Ole e 1.0103 protein [Olea europea] (gi|2465129) were identified as nonglycosylated species. These results, partially in disagreement with Swiss-Prot annotation, were validated by matching the MALDI MS/MS spectra of the natural tryptic mixture with those obtained after deglycosylation.

Ole e 1 (NCBI entry gi vertical bar 14424429) is the major allergen of Oleaceae family. Multiple isoforms and variants are present in varying degrees of distribution. In this report, we present a new approach to the resolution of multiple forms of Ole e 1 from whole antigen extracts, based on a preliminary chemical fractionation procedure followed by MALDI MS and MS/MS measurements. The characterization of Ole e 1 isoallergens was accomplished through the identification of the amino acid sequence including the glycosylation site and the structure of the glycan moieties. The structure feature of the-identified Ole e 1.0102 (gi vertical bar 2465127), main olive allergen [Olea europaea] (gi vertical bar 13195753), Major pollen allergen Ole e 1 (gi vertical bar 33329740) and Ole e 1c (gi vertical bar 1362131) is represented by the point mutation K(106) -> I and by the presence of a glycan moiety. Two other variants Major pollen allergen (Allergen Ole e1) (Ole e I) (gi vertical bar 14424429) and Ole e 1.0103 protein [Olea europea](gi vertical bar 2465129) were identified as nonglycosylated species. These results, partially in disagreement with Swiss-Prot annotation, were validated by matching the MALDI MS/MS spectra of the natural tryptic mixture with those obtained after deglycosylation. RI NAPOLI, ANNA/B-5250-2011; Di Donna, Leonardo/D-5707-2011